Conventionally, there has been known a pump that discharges a fluid from one end side to the other end side of a tube by rotating a pair of pressers to thereby press the tube (for example, refer to Japanese Unexamined Patent Application, Publication No. Hei 5-263765).
In the pump disclosed in Japanese Unexamined Patent Application, Publication No. Hei 5-263765, a rotation shaft to which one presser is coupled is projected upwardly, and a rotation shaft to which the other presser is coupled is projected downwardly. In the pump disclosed in Japanese Unexamined Patent Application, Publication No. Hei 5-263765, drive forces of a pair of electric motors are transmitted to the rotation shafts projecting upwardly and downwardly by a pair of reducers, respectively, and the pair of pressers is rotated at non-constant velocities to thereby discharge the fluid by small pulsation.